syzbot

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BUG: KCSAN: data-race in bio_endio / blk_throtl_bio

read to 0xffff8881237ca494 of 2 bytes by interrupt on cpu 1:
 bio_remaining_done block/bio.c:1760 [inline]
 bio_endio+0x3e/0x400 block/bio.c:1790
 req_bio_endio block/blk-core.c:245 [inline]
 blk_update_request+0x427/0x7b0 block/blk-core.c:1464
 scsi_end_request+0x6b/0x360 drivers/scsi/scsi_lib.c:576
 scsi_io_completion+0x11d/0xc80 drivers/scsi/scsi_lib.c:960
 scsi_finish_command+0x283/0x380 drivers/scsi/scsi.c:228
 scsi_softirq_done+0x259/0x280 drivers/scsi/scsi_lib.c:1476
 blk_done_softirq+0x1eb/0x250 block/blk-softirq.c:37
 __do_softirq+0x115/0x33f kernel/softirq.c:292
 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1082
 do_softirq.part.0+0x6b/0x80 kernel/softirq.c:337
 do_softirq kernel/softirq.c:329 [inline]
 __local_bh_enable_ip+0x76/0x80 kernel/softirq.c:189
 local_bh_enable include/linux/bottom_half.h:32 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:706 [inline]
 ip6_finish_output2+0x730/0xf60 net/ipv6/ip6_output.c:117
 ip6_fragment+0x108c/0x1270 net/ipv6/ip6_output.c:860
 __ip6_finish_output net/ipv6/ip6_output.c:140 [inline]
 __ip6_finish_output+0x2f9/0x330 net/ipv6/ip6_output.c:127
 ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x108/0x290 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 ip6_local_out+0x74/0x90 net/ipv6/output_core.c:179
 ip6_send_skb+0x53/0x110 net/ipv6/ip6_output.c:1795
 ip6_push_pending_frames+0x9d/0xc0 net/ipv6/ip6_output.c:1815
 rawv6_push_pending_frames net/ipv6/raw.c:613 [inline]
 rawv6_sendmsg+0x1e59/0x2340 net/ipv6/raw.c:956
 inet_sendmsg+0x6d/0x90 net/ipv4/af_inet.c:807
 sock_sendmsg_nosec net/socket.c:639 [inline]
 sock_sendmsg+0x9f/0xc0 net/socket.c:659
 __sys_sendto+0x21f/0x320 net/socket.c:1985
 __do_sys_sendto net/socket.c:1997 [inline]
 __se_sys_sendto net/socket.c:1993 [inline]
 __x64_sys_sendto+0x89/0xb0 net/socket.c:1993
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8881237ca494 of 2 bytes by task 9713 on cpu 0:
 bio_set_flag include/linux/bio.h:239 [inline]
 blk_throtl_bio+0x162/0x1a90 block/blk-throttle.c:2270
 blkcg_bio_issue_check include/linux/blk-cgroup.h:602 [inline]
 generic_make_request_checks+0x6fa/0x1040 block/blk-core.c:964
 generic_make_request+0x3e/0x700 block/blk-core.c:1020
 __blk_queue_split+0x779/0xc40 block/blk-merge.c:347
 blk_mq_make_request+0x104/0xf60 block/blk-mq.c:1920
 generic_make_request block/blk-core.c:1066 [inline]
 generic_make_request+0x196/0x700 block/blk-core.c:1008
 submit_bio+0x96/0x3c0 block/blk-core.c:1192
 iomap_dio_submit_bio.isra.0+0xfc/0x120 fs/iomap/direct-io.c:70
 iomap_dio_bio_actor+0x40a/0x960 fs/iomap/direct-io.c:306
 iomap_dio_actor+0x87/0x3a0 fs/iomap/direct-io.c:382
 iomap_apply+0x20d/0x6a0 fs/iomap/apply.c:80
 iomap_dio_rw+0x67e/0x9a0 fs/iomap/direct-io.c:498
 ext4_dio_write_iter fs/ext4/file.c:438 [inline]
 ext4_file_write_iter+0xc38/0xd40 fs/ext4/file.c:545
 call_write_iter include/linux/fs.h:1902 [inline]
 new_sync_write+0x388/0x4a0 fs/read_write.c:483
 __vfs_write+0xb1/0xc0 fs/read_write.c:496
 vfs_write fs/read_write.c:558 [inline]
 vfs_write+0x18a/0x390 fs/read_write.c:542
 ksys_write+0xd5/0x1b0 fs/read_write.c:611
 __do_sys_write fs/read_write.c:623 [inline]
 __se_sys_write fs/read_write.c:620 [inline]
 __x64_sys_write+0x4c/0x60 fs/read_write.c:620
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 9713 Comm: syz-executor.4 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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